JP4320482B2 - Fuel cell electrode and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel cell electrode and a method for producing the same.
[0002]
[Prior art]
A solid polymer electrolyte fuel cell uses an ion exchange membrane as an electrolyte, and anode and cathode electrodes each having a catalyst layer and a gas diffusion layer containing a conductive porous body are bonded to both sides of the ion exchange membrane. It is a device that generates electricity through an electrochemical reaction by supplying hydrogen to the anode and oxygen to the cathode. The electrochemical reaction occurring at each electrode is shown below.
[0003]
Anode: H ₂ → 2H ⁺ + 2e
Cathode: 1 / 2O ₂ + 2H ⁺ + 2e → H ₂ O
Total reaction: H ₂ + 1 / 2O ₂ → H ₂ O
As is clear from this reaction formula, the reaction of each electrode proceeds only at the three-phase interface where the active material gas (hydrogen or oxygen), proton (H ⁺ ) and electron (e) can be exchanged simultaneously. To do.
[0004]
As shown in FIG. 5, the fuel cell electrode has a porous structure in which catalyst particles 51 and solid polymer electrolyte 52 are mixed and distributed in three dimensions, and a plurality of pores 54 are formed inside. Catalyst layer 56 and a gas diffusion layer 58 including a conductive porous body 57.
[0005]
The gas diffusion layer 58 is provided with a certain space in the surface layer of the catalyst layer 56 to secure a flow path for carrying oxygen and hydrogen, which are active materials supplied from the outside of the battery, to the surface layer of the catalyst layer 56, and the catalyst layer of the cathode It plays a role of ensuring a flow path for discharging the water generated in step 1 from the surface layer of the catalyst layer 56 to the outside of the battery system.
[0006]
On the other hand, in the catalyst layer 56, the catalyst particles 51 form an electron conduction channel, the solid electrolyte 52 forms a proton conduction channel, and the pores 54 carry oxygen or hydrogen carried to the surface of the catalyst layer 56 to the deep part of the electrode. A supply / discharge channel for supplying and discharging water generated in the deep part of the electrode (cathode) to the surface layer of the electrode is formed. These three channels spread three-dimensionally in the catalyst layer 56, and an infinite number of three-phase interfaces capable of simultaneously transferring gas, proton (H ⁺ ), and electrons (e) are formed. A place is offered.
[0007]
In FIG. 5, reference numeral 53 denotes PTFE (polytetrafluoroethylene) particles, which play a role of imparting water repellency in the pores 54 of the catalyst layer 56 and on the surface layer. Reference numeral 55 denotes an ion exchange membrane.
Here, the ion exchange membrane 55 serving as an electrolyte needs to be operated while keeping the inside of the battery in a wet state in order to show good proton conductivity in a water-containing state. Therefore, moisture management of the ion exchange membrane is performed by appropriately humidifying the hydrogen and oxygen supplied to the anode and the cathode so that the ion exchange membrane 55 is not dried.
[0008]
[Problems to be solved by the invention]
In the solid polymer electrolyte fuel cell, since pores in the catalyst layer form oxygen or hydrogen supply channels, water accumulates on the surface of the catalyst layer due to humidification of the supply gas as these active materials. Water blocks the gas supply inlet of the pores, hinders the gas supply into the pores, or water accumulates in the pores, and the supply of active material to the three-phase interface of the catalyst layer, especially the deep part of the electrode is delayed. In some cases, the working area is actually reduced and the battery performance cannot be taken out sufficiently. For this reason, moderate water repellency is imparted to the gas diffusion layer and the catalyst layer including the conductive porous body so that water does not accumulate.
[0009]
For example, in the case of carbon paper (thickness of 1.5 mm), which is a commonly used sintered carbon fiber, the carbon porous material is immersed in a PTFE particle dispersion solution to provide PTFE particles. Then, PTFE is coated on the carbon fiber surface by baking at about 350 ° C. for 15 minutes in a nitrogen atmosphere.
[0010]
On the other hand, imparting water repellency to the catalyst layer is achieved by applying PTFE particles to a catalyst layer paste composed of catalyst-supported carbon particles in which noble metal particles such as platinum are supported in a highly dispersed state on a carbon particle carrier that is catalyst particles and a solid polymer electrolyte solution. This is done by mixing the dispersion solution.
[0011]
However, at present, the water repellency of the catalyst layer and the conductive porous body is not sufficient, and in order to increase the output of the battery, let's improve the proton conductivity of the ion exchange membrane by supplying high-temperature and humidified gas. As a result, water accumulates in the pores of the catalyst layer and in the surface layer, and the supply of active material to the three-phase interface of the catalyst layer, particularly to the deep part of the electrode, is stagnated, the actual working area is reduced, and the battery performance can be sufficiently extracted. There is no problem. In particular, since water is generated at the cathode during the reaction, water tends to accumulate in the pores.
[0012]
In order to avoid this, for example, in the catalyst layer, it is possible to increase the mixing ratio of the PTFE particle dispersion solution applied at the time of preparation of the catalyst layer to increase the water repellency of the catalyst layer, thereby making it difficult for water to accumulate in the pores and in the surface layer. What is necessary is that the proportion of the catalyst-supported carbon, the solid polymer electrolyte, and the pores decreases by the volume increase in the electrode of the PTFE particles, and the electron conduction channel, the proton conduction channel, oxygen or hydrogen, and the product water. The formation of the supply / discharge channel is obstructed, and the output of the battery is reduced.
[0013]
In addition, it is only necessary to increase the coating amount of the PTFE dispersion solution when imparting water repellency to the conductive porous body. However, if the amount is increased too much, the PTFE particles block the pores of the conductive porous body, and instead supply gas. Will be inhibited.
[0014]
In view of the above, the present invention improves the water repellency of the fuel cell electrode while preventing the occurrence of the above-described problems, thereby improving the performance of the fuel cell electrode.
[0015]
[Means for Solving the Problems]
Fuel cell electrode of the present invention are those having a catalyst layer containing a solid polymer electrolyte and catalyst particles and porous resin.
[0016]
The electrode for a fuel cell according to the first invention of the present application is an electrode for a fuel cell having a catalyst layer containing a solid polymer electrolyte and catalyst particles, and has an ion exchange group at a portion corresponding to the pore of the catalyst layer or / and on the surface thereof. It is characterized by comprising a water-repellent porous resin that does not .
[0017]
Fuel cell electrode according to the second aspect of the invention is provided with a gas diffusion layer for a fuel cell electrode comprising a conductive porous body according to claim 1, wherein the electrically conductive porous body, having an ion-exchange group It is characterized by having no water-repellent porous resin.
[0018]
In this case, the conductive porous body is more preferably made of a carbon material.
[0019]
The third invention of the present application is a method for producing an electrode for a fuel cell having a water-repellent porous resin not having an ion exchange group of the first invention of the present application, wherein the catalyst layer has a repellent property having no ion exchange group. A solution in which an aqueous resin is dissolved in a solvent a is included , and then the solvent a is replaced with a solvent b that is insoluble in the resin and compatible with the solvent a. .
Further, the fourth invention of the present application is a method for producing an electrode for a fuel cell comprising a water-repellent porous resin not having an ion exchange group of the second invention of the present application , in which the catalyst layer and the gas diffusion layer are laminated. After adding a solution in which water-repellent resin having no ion exchange group is dissolved in solvent a, the solvent a is insoluble in the resin and is compatible with the solvent a. It is characterized by undergoing a replacement step.
[0020]
In any of the above-described electrodes, a solid polymer electrolyte having an ion exchange function is used, and a porous resin having a water repellent property having no ion exchange function is used . And as resin which comprises the said porous resin, a fluororesin is more preferable and it is preferable to use a polyvinylidene fluoride (PVdF) type-resin among these.
[0021]
A third invention of the present application is a method for producing an electrode for a fuel cell comprising a water-repellent porous resin having no ion exchange group of the first invention of the present application , comprising a solid polymer electrolyte and a catalyst A solution in which a water-repellent resin not having an ion exchange group is dissolved in a solvent a in a catalyst layer containing particles, and then insoluble in the resin and compatible with the solvent a This is performed by immersing it in b, and replacing the solvent a with a solvent b that is insoluble in the resin and compatible with the solvent a.
[0022]
A fourth invention of the present application is a method for producing an electrode for a fuel cell provided with a water-repellent porous resin not having an ion exchange group of the second invention of the present application. That is, when the fuel cell electrode has a structure in which a solid polymer electrolyte, a catalyst layer containing catalyst particles, and a conductive porous body are laminated, the lamination of the catalyst layer and the gas diffusion layer is performed. After including a solution of a water-repellent resin having no ion exchange group in the solvent in the solvent a, the laminate is immersed in the solvent b that is insoluble in the resin and compatible with the solvent a. The solvent a is replaced with a solvent b that is insoluble in the resin and compatible with the solvent a.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail by explaining the structural examples of the fuel cell electrode according to the present invention with reference to the drawings. 2, 3 and 4 are schematic views showing structural examples of fuel cell electrodes according to the present invention.
[0024]
As shown in these drawings, the catalyst layer comprising the solid polymer electrolyte and the catalyst particles referred to in the present invention is a mixture of the catalyst particles 21, 31, 41 and the solid polymer electrolytes 22, 32, 42. These are three-dimensionally distributed and based on a porous catalyst layer in which a plurality of pores 23, 33, 43 are formed. Basically, the catalyst particles have electron conduction channels. The solid electrolyte forms a proton conducting channel and the pores form a supply and discharge channel of oxygen or hydrogen and the product water.
[0025]
The fuel cell electrode shown in FIG. 2 is provided with a porous resin 24 having a number of three-dimensionally communicating holes in a portion corresponding to the pores of the catalyst layer, and the fuel cell electrode shown in FIG. 4 is provided with a porous resin 34 having a large number of three-dimensional communicating holes on the surface of the layer, and the electrode for a fuel cell shown in FIG. A porous resin 44 having a large number of pores is provided, and the catalyst layer and the conductive porous body are provided with a porous resin. 2 to 4, a water-repellent resin having no ion exchange group is used as the porous resin.
[0026]
In addition, since the pores are eliminated by disposing a water-repellent porous resin having no ion exchange group in the pores, this portion is called a pore equivalent portion. In the figure, reference numerals 25, 35, and 45 denote ion exchange membranes, and reference numerals 26, 36, and 46 denote carbon electrode substrates made of a sintered body of porous conductive substrate carbon fibers. Further, if necessary, PTFE particles can be provided in the catalyst layer as usual.
[0027]
According to the present invention, the water repellency of the pore-corresponding portion or / and the surface layer is increased by disposing the water-repellent resin having no porous ion exchange function on the pore-corresponding portion or / and the surface layer of the catalyst layer. . This prevents water from accumulating on the surface layer of the catalyst layer and covering the pores, and also prevents water from stagnation in the pores. The catalyst layer is supplied without stagnation to the three-phase interface of the layer, and high activation of the catalyst layer is achieved.
[0028]
In addition, even if it arrange | positions the water-repellent porous resin which does not have an ion exchange group only in a pore like FIG. 2, or only on the surface layer like FIG. 3, the effect of this invention is acquired, As shown in FIG. 4, higher activity can be achieved by arranging a water-repellent porous resin having no ion exchange group in the pore equivalent portion of the base of the catalyst layer and on the surface layer.
[0029]
In addition , the water-repellent porous resin having no ion exchange group may be disposed on the entire surface of the catalyst layer base as shown in these figures, but a part of the surface layer, and / or You may arrange | position to a part in pore.
[0030]
As the catalyst particles used in the electrode of the present invention, platinum group metals such as platinum, rhodium, ruthenium, iridium, palladium, osnium and alloy particles thereof, or catalyst-carrying carbon carrying these catalysts are suitable. The molecular electrolyte is preferably made of an ion exchange resin, preferably perfluorosulfonic acid or a styrene-divinylbenzene sulfonic acid type solid polymer electrolyte.
[0031]
Here, the pores of the porous resin are preferably open cells so that the active material can be smoothly supplied and discharged. The pore diameter is preferably 1 μm or less, more preferably 0.5 μm or less, and the porosity of the effective resin is preferably 45% or more in terms of gas supply, water discharge, and the like. . It is preferable to use a solvent extraction method as a method for producing a porous polymer capable of obtaining dense open cells. That is, by replacing the solvent a in the solution in which the resin is dissolved with a solvent b insoluble in the resin and compatible with the solvent a, the solvent a in the solution in which the resin is dissolved is extracted. The part from which the solvent a has been removed becomes pores to obtain a porous resin.
[0032]
Here, the porous resin used in the present invention is polyether such as polyvinyl chloride, polyacrylonitrile, polyethylene oxide, polypropylene oxide, polyacrylonitrile, vinylidene fluoride polymer, polyvinylidene chloride, polymethyl methacrylate, polymethyl acrylate. , Polyvinyl alcohol, polymethacrylonitrile, polyvinyl acetate, polyvinyl pyrrolidone, polyethyleneimine, polybutadiene, polystyrene, polyisoprene, or derivatives thereof may be used alone or in combination, and constitutes the above resin A resin obtained by copolymerization of various monomers may be used, but preferably a fluororesin having high water repellency, such as ethylene trifluoride chloride copolymer (PCTFE), vinylidene fluoride polymer (PVdF), fluoropolymer. Fluorinated homopolymers such as vinyl fluoride polymer (PVF), ethylene / tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene / hexafluoropropylene copolymer (EPE), vinylidene fluoride copolymer Fluorine-containing copolymers such as are preferable, and a mixture thereof may be used.
[0033]
Then, when a porous fluororesin is produced by the previous solvent extraction method, fine and uniform pores are obtained, so that PVdF homopolymer, vinylidene fluoride / hexafluoropropylene copolymer (P (VdF-HFP )) Or a polyvinylidene fluoride (PVdF) resin such as a vinylidene fluoride / tetrafluoroethylene copolymer (P (VdF-TFP)). Among them, a vinylidene fluoride polymer (PVdF) excellent in water repellency or a soft vinylidene fluoride / hexafluoropropylene copolymer (P (VdF-HFP)) that is easy to handle is preferable.
[0034]
Solvent a that dissolves the resin may be any as long as it dissolves the resin. Carbonic acid esters such as dimethylformamide, propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate, dimethyl ether, diethyl ether, and ethyl methyl ether , Ethers such as tetrahydrofuran, dimethylacetamide, 1-methyl-pyrrolidinone, n-methyl-pyrrolidone and the like.
[0035]
As the extraction solvent b, water or a mixed solution of water and alcohol is preferable because it is inexpensive.
[0036]
In these combinations, polyvinylidene fluoride (PVdF) or P (VdF-HFP) dissolved in n-methylpyrrolidone (NMP) is extracted with water or a mixed solution of water and alcohol. It is preferable in terms of uniformity of pore diameter.
[0037]
Such an electrode for a fuel cell of the present invention is formed, for example, by forming a catalyst layer paste containing catalyst-carrying carbon particles, a solid polymer electrolyte solution and, if necessary, a PTFE particle dispersion solution into a polymer film (generally, A conventional catalyst layer produced by a method such as heating and drying after a film thickness of 3 to 30 μm), or catalyst-carrying carbon particles in which noble metal particles such as platinum are supported in a highly dispersed manner on a carbon particle carrier and, if necessary, Is a method of forming a catalyst layer paste to which a PTFE particle dispersion solution has been added on a polymer film (generally having a film thickness of 3 to 30 μm), heating and drying, and then applying and impregnating a solid polymer electrolyte solution thereon. A solution obtained by dissolving a resin in a solvent a in a conventional catalyst layer thus prepared is applied or dipped, and then insoluble in the resin. Can be obtained by replacing the solvent a solvent b which with a compatible.
Alternatively, after forming a catalyst layer paste (generally having a film thickness of 3 to 30 μm) on the conductive porous body, the catalyst-supporting carbon particles, the solid polymer electrolyte solution, and, if necessary, the PTFE particle dispersion solution are added. , A conventional electrode produced by a method such as heating and drying, or a catalyst-supported carbon particle in which noble metal particles such as platinum are supported on a carbon particle support in a highly dispersed state and a catalyst in which a PTFE particle-dispersed solution is added if necessary A conventional electrode produced by forming a layer paste on a conductive porous body (generally having a film thickness of 3 to 30 μm), heating and drying, and then applying and impregnating a solid polymer electrolyte solution thereon Then, after a solution obtained by dissolving the resin in the solvent a is included by coating or dipping, the solvent a is placed in a solvent b that is insoluble in the resin and compatible with the solvent a. It can be obtained by.
[0038]
In particular, according to the latter production method, in a fuel cell electrode including a catalyst layer containing a solid polymer electrolyte and catalyst particles and a gas diffusion electrode containing a conductive porous body, the catalyst layer and the conductivity Since the porous body contains a water-repellent porous resin having no ion exchange group , a fuel cell electrode having high activity can be expected. In this case, if a fluororesin having high water repellency is used, there is no need to impart water repellency to the conductive porous body in advance, and the porous resin disposed in the conductive porous body plays a role in this. Take on.
[0039]
Here, as the conductive porous body, foamed nickel, titanium fiber sintered body or the like can be used, but a porous carbon base material is preferable from the viewpoint of conductivity, weight, etc., and a sintered body of carbon fiber, etc. Is good.
[0040]
【Example】
The present invention will be described below with reference to preferred embodiments.
[0041]
[Example 1]
A conductive porous material is made of a catalyst layer paste made of platinum-supported carbon (Tanaka Kikinzoku, 10V30E: Valcan XC-72 with 30 wt% platinum supported) and a solid polymer electrolyte solution (Aldrich, Nafion 5 wt% solution). An electrode obtained by coating on a carbon sheet (0.5 mm) and drying at 120 ° C. for 1 hour in a nitrogen atmosphere was vacuum impregnated with a PVdF / NMP solution (PVdF concentration: 15 wt%), followed by water It was immersed in it for 10 minutes to obtain a fuel cell electrode A.
[0042]
The electrode A has a structure in which an effective PVdF resin is disposed in the pores of the catalyst layer and on the surface layer, and further on the conductive porous body.
[0043]
The amount of platinum-supporting carbon at the time of preparing the paste was adjusted so that the amount of platinum in electrode A was about 1.0 mg / cm ² .
[0044]
Furthermore, the electrode A was joined to both surfaces of an ion exchange membrane (manufactured by DuPont, Nafion, film thickness of about 50 μm) with a hot press (140 ° C.), and assembled into a single cell of a fuel cell to obtain a cell A.
[0045]
[Example 2]
A paste made of platinum-supported carbon (Tanaka Kikinzoku, 10V30E: 30% by weight of platinum supported on Valcan XC-72) and a solid polymer electrolyte solution (Aldrich, Nafion 5 wt% solution) is placed on a polymer film (PFA). The catalyst layer obtained by applying and air-drying for about 1 hour was joined to both surfaces of an ion exchange membrane (DuPont, Nafion, film thickness of about 50 μm) with a hot press (140 ° C.). An exchange membrane assembly was obtained. Further, a PVdF / NMP solution (PVdF concentration: 15 wt%) was applied to the surface of the catalyst layer by brushing, and then immersed in water for 10 minutes to obtain a catalyst layer B-ion exchange membrane assembly.
[0046]
The catalyst layer B has a structure in which a porous PVdF resin is mainly disposed on the surface layer.
[0047]
The amount of platinum-supported carbon at the time of preparing the paste was adjusted so that the amount of platinum on one surface of the catalyst layer B-ion exchange membrane assembly was about 1.0 mg / cm ² .
[0048]
A conductive porous carbon sheet (0.5 mm) imparted with water repellency to serve as a gas diffusion layer on both surfaces of this joined body was joined by hot pressing, and assembled into a single cell of a fuel cell to obtain cell B. .
[Comparative Example 1]
Platinum-supported carbon (manufactured by Tanaka Kikinzoku, 10V30E: 30% by weight of platinum supported on Valcan XC-72), solid polymer electrolyte solution (manufactured by Aldrich, 5% by weight Nafion solution), and PTFE particle dispersion solution (manufactured by DuPont Mitsui Chemicals, A paste made of Teflon 30J) is coated on a conductive porous carbon electrode substrate (0.5 mm) imparted with water repellency, and dried in a nitrogen atmosphere at 120 ° C. for 1 hour, and fuel cell electrode C Got.
[0049]
The amount of platinum-supporting carbon at the time of preparing the paste was adjusted so that the amount of platinum in electrode C was about 1.0 mg / cm ² .
[0050]
Further, the electrode C was joined to both surfaces of an ion exchange membrane (manufactured by DuPont, Nafion, film thickness of about 50 μm) with a hot press (140 ° C.), and assembled into a single cell of a fuel cell to obtain a cell C.
[0051]
[Comparative Example 2]
Platinum-supported carbon (manufactured by Tanaka Kikinzoku, 10V30E: 30% by weight of platinum supported on Valcan XC-72), solid polymer electrolyte (manufactured by Aldrich, 5% by weight of Nafion) and PTFE particle dispersion (manufactured by Mitsui Dupont Fluorochemical, Teflon) 30J) is applied onto a polymer film (PFA) and naturally dried for about 1 hour. An electrode obtained by hot pressing (140 ° C.) is subjected to ion exchange membrane (manufactured by DuPont, Nafion, membrane). The catalyst layer D-ion exchange membrane assembly was obtained by bonding to both surfaces having a thickness of about 50 μm.
The amount of platinum-supported carbon at the time of preparing the paste was adjusted so that the amount of platinum on one side of the catalyst layer D-ion exchange membrane assembly was about 1.0 mg / cm ² .
[0052]
Conductive porous carbon sheets (0.5 mm) imparted with water repellency to serve as gas diffusion layers on both sides of this joined body were joined by hot pressing, and assembled into a single cell of a fuel cell to obtain cell D. .
[0053]
FIG. 1 shows current-voltage characteristics when oxygen and hydrogen are used as the supply gas of these cells. The operating conditions were that the supply gas pressure was 2 atm, and each was humidified by bubbling in a sealed water bath at 80 ° C. The operating temperature of the cell was 75 ° C., and the holding time during measurement at each current value was 5 minutes.
[0054]
FIG. 1 shows that the cells (A and B) according to the present invention have a higher output voltage at each current density than the conventional cells (C and D). In particular, it can be seen that the output of A in which porous PVdF is arranged in the pores of the catalyst layer and in the surface layer is higher than that of B. This is because, according to the present invention, in order to arrange porous PVdF having high water repellency in the pores of the catalyst layer and / or in the surface layer, it is possible to ensure the active material hydrogen and oxygen to the deep part of the electrode. This is because supply is possible and the area of the catalyst layer actually acting is larger than that of the conventional catalyst layer. In particular, the cell A in which porous PVdF was disposed in the pores of the catalyst layer and in the surface layer showed good characteristics.
[0055]
【The invention's effect】
According to the electrode for a fuel cell of the present invention, the electrode area that actually acts is larger than that of a conventional electrode, and a high-performance fuel cell can be manufactured. Moreover, according to the manufacturing method of the present invention, an electrode capable of manufacturing a high-performance fuel cell can be manufactured.
[Brief description of the drawings]
FIG. 1 is a graph showing current-voltage characteristics of a cell.
FIG. 2 is a schematic diagram showing the structure of a fuel cell electrode according to the present invention.
FIG. 3 is a schematic diagram showing the structure of a fuel cell electrode according to the present invention.
FIG. 4 is a schematic diagram showing the structure of a fuel cell electrode according to the present invention.
FIG. 5 is a schematic view showing the structure of a conventional fuel cell electrode.
[Explanation of symbols]
21, 31, 41: catalyst particles 22, 32, 42: solid polymer electrolytes 23, 33, 43: pores 24, 34, 44: porous resin 25, 35, 45: ion exchange membrane 26, 36, 46: Carbon electrode base material

Claims (4)

  In a fuel cell electrode having a catalyst layer containing a solid polymer electrolyte and catalyst particles, a water repellent porous resin not having an ion exchange group is provided on the pore equivalent part or / and the surface of the catalyst layer. An electrode for a fuel cell.   The fuel cell electrode includes a gas diffusion layer including a conductive porous body, and the conductive porous body includes a water-repellent porous resin having no ion exchange group. Item 10. The fuel cell electrode according to Item 1. After the catalyst layer contains a solution in which a water-repellent resin having no ion exchange group is dissolved in the solvent a, the solvent a is insoluble in the resin and is compatible with the solvent a. A method for producing an electrode for a fuel cell comprising a water-repellent porous resin having no ion exchange group according to claim 1, wherein the step of substituting with is performed. After the laminated body of the catalyst layer and the gas diffusion layer contains a solution obtained by dissolving a water-repellent resin not having an ion exchange group in the solvent a, the solvent a is insoluble in the resin and the solvent 3. The method for producing an electrode for a fuel cell comprising a water-repellent porous resin having no ion exchange group according to claim 2, wherein a step of substituting with a solvent b compatible with a is performed.

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